GB425522A - Improvements in or relating to sewing machines and attachments therefor - Google Patents

Abstract

425,522. Sewing-machines. WURKER GES., 16, Pirnaische Strasse, Dresden, Germany. July 20, 1934, Nos. 21330, 21331, and 21332. Convention dates, July 20, 1933, Oct. 28, 1933, and June 16, 1934. [Class 112] In an attachment for blind-stitching driven by the needle bar, the stitch forming members and the stitching point are situated at the side of the needle bar and the needle rocking arm is accelerated by a cam control in penetrating the work and is retarded on leaving the work. The attachment is driven by the engagement of a projection on the reciprocating needle bar in a recess 6 of the lever 5. The lever 5 actuates a shaft 7 which rocks a sector 8. A slot 10 in the sector 8 rocks a lever 12 in both directions to rock the shaft 13 carrying the arm 14 supporting the curved needle 32. The speed of the needle on penetration and retraction is determined by the curvature of the slot 10. The rocking needle arm 14 also drives the looper 18, the point 19 of which takes off the thread loop from the rear and brings it sideways to the front. The looper 18 is driven by a bifurcated extension 24 on the arm 14, Fig. 3. The thread passes through tension discs 25, 26 and through eyes 29, 30, 31, 33, so that movement of the arm 14 tightens the stitch. The lever 5 actuates the feeding device by a pawl 35 and ratchet wheel 37. The ratchet wheel actuates a concentric toothed wheel 39 which turns a smaller toothed wheel 40 carrying the feed roller 41. The feed roller 41 projects through the bottom 43 of the casing of the attachment and rests on the cloth 44. A base plate 45 carries a projection 46 opposite the feed roller to bend the work which then passes between the legs of the presser foot and the bender 51. The height of the bender 51 is adjusted by the thumb screw, Fig. 4.